Przemysław Głowacki - Academia.edu (original) (raw)
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Papers by Przemysław Głowacki
Data is presented on 166 previously unknown energy levels of Th+ ions, observed using resonant tw... more Data is presented on 166 previously unknown energy levels of Th+ ions, observed using resonant two-step laser excitation of trapped ions. The levels are of even parity and within the energy range from 7.8 to 9.8 eV. Observed lines are listed.<br> The observed levels can be relevant for the excitation or decay of the Th-229m isomeric nuclear state which lies in this energy range.
Within this work investigations of the hyperfine structure of tantalum atom with LIF (Laser Induc... more Within this work investigations of the hyperfine structure of tantalum atom with LIF (Laser Induced Fluorescence) method in a hollow cathode discharge were performed. Two hitherto unclassified spectral lines were excited: λ=4835.614 Å and λ=4997.192 Å. For both transitions values of quantum number J (total angular momentum of electron shell) of the levels involved were determined. On the basis of hyperfine structure constants A and B the lower levels of the transitions could be identified. Values of energies of the lower levels and wavenumbers of the excited transitions yielded energy value of the common, as it proved, upper level for both transitions. The odd parity level of the energy 47418.095 ± 0.011 cm -1 , with total electron angular momentum quantum number J=1/2 and the value of hyperfine structure magnetic dipole interaction constant A=-661 ± 13 MHz (for J=1/2 electric quadrupole interaction constant B=0) is a newly discovered electron level of tantalum atom. On the basis of...
Physical Review A, 2018
The thorium nucleus with mass number A = 229 has attracted much interest because its extremely lo... more The thorium nucleus with mass number A = 229 has attracted much interest because its extremely low lying first excited isomeric state at about 8 eV opens the possibility for the development of a nuclear clock. However, neither the exact energy of this nuclear isomer nor properties, such as nuclear magnetic dipole and electric quadrupole moment are known to a high precision so far. The latter can be determined by investigating the hyperfine structure of thorium atoms or ions. Due to its electronic structure and the long lifetime of the nuclear isomeric state, Th 2+ is especially suitable for such kind of studies. In this letter we present a combined experimental and theoretical investigation of the hyperfine structure of the 229 Th 2+ ion in the nuclear ground and isomeric state. A very good agreement between theory and experiment is found for the nuclear ground state. Moreover, we use our calculations to confirm the recently presented experimental value for the nuclear magnetic dipole moment of the thorium nuclear isomer, which was in contradiction to previous theoretical studies.
The European Physical Journal Special Topics, 2013
The experimental work of L. Windholz, G.H. Guthöhrlein and co-workers, concerning observation of ... more The experimental work of L. Windholz, G.H. Guthöhrlein and co-workers, concerning observation of the tantalum spectrum, yield many information about new energy levels and hyperfine structure splitting. We contribute the results of the complex parametric studies of the fine-and hyperfine structure of the mentioned element up to second-order of perturbation theory, including the effects of closed shell-open shell excitations. The work has been performed for the systems including 47 even configurations. The values of the radial parameters describing the one-and many-body interactions effects on atomic structure are given. We predicted values of energy levels and their A-and B-hyperfine structure constants, also for experimentally levels not observed up to now.
Using resonant two-step laser excitation of trapped ^232Th^+ ions, we observe 166 previously unkn... more Using resonant two-step laser excitation of trapped ^232Th^+ ions, we observe 166 previously unknown energy levels of even parity within the energy range from 7.8 to 9.8 eV and angular momenta from J=1/2 to 7/2. We also classify the high-lying levels observed in our earlier experiments by the total angular momentum and perform ab-initio calculations to compare their results with the observed level density. The observed levels can be relevant for the excitation or decay of the ^229mTh isomeric nuclear state which lies in this energy range. The high density of electronic levels promises a strongly enhanced electronic bridge excitation of the isomer in ^229Th^+.
Supplementary Information Nature 556:321-325. The figures show 29 of the 35 two-step excitation s... more Supplementary Information Nature 556:321-325. The figures show 29 of the 35 two-step excitation spectra recorded using the trap at LMU with copropagating beam configuration (six spectra do not contain detectable resonance features) and all spectra with counterpropagating configuration. The tables list the resonances and the corresponding transitions. See contents page for details.
Nature, Apr 1, 2018
The isotope Th is the only nucleus known to possess an excited state Th in the energy range of a ... more The isotope Th is the only nucleus known to possess an excited state Th in the energy range of a few electronvolts-a transition energy typical for electrons in the valence shell of atoms, but about four orders of magnitude lower than typical nuclear excitation energies. Of the many applications that have been proposed for this nuclear system, which is accessible by optical methods, the most promising is a highly precise nuclear clock that outperforms existing atomic timekeepers. Here we present the laser spectroscopic investigation of the hyperfine structure of the doubly charged Th ion and the determination of the fundamental nuclear properties of the isomer, namely, its magnetic dipole and electric quadrupole moments, as well as its nuclear charge radius. Following the recent direct detection of this long-sought isomer, we provide detailed insight into its nuclear structure and present a method for its non-destructive optical detection.
Journal of Physics B: Atomic, Molecular and Optical Physics, 2014
ABSTRACT Laser excitation of an Ar-La plasma, generated in a hollow cathode discharge lamp, has a... more ABSTRACT Laser excitation of an Ar-La plasma, generated in a hollow cathode discharge lamp, has allowed to us observe a huge number of spectral lines that could not be interpreted as transitions between already known La energy levels. From the observed hyperfine structure patterns and fluorescence lines, we derived 37 new La levels, all with even parity, in the energy range between 38 000 cm(-1) and 43 000 cm(-1). The existence of these levels was then proved by excitations from other known lower levels.
Physical Review Letters, 2018
The strong La line 6520.644 Å is present in a Fourier Transform Spectrum (signal to noise ratio o... more The strong La line 6520.644 Å is present in a Fourier Transform Spectrum (signal to noise ratio of 240), but its wavelength in commonly used tables (e.g. [1]) is given as 6520.770 Å, while in [2] the wavelength is given as 6520.74 Å, unclassified, with the remark “h ” (hazy). The line could not be classified using known energy levels of the La atom (La I) and its first ion (La II). It appears as a single broadened peak. By a combination of laser optogalvanic spectroscopy, laser-induced fluorescence and Doppler-reduced saturation spectroscopy we could introduce a new even parity La I energy level, 35449.041 cm −1, J = 13/2, with hyperfine (hf) constants A = −8.0(5) MHz, B = 10(10) MHz. For a second, up to now unknown neighbouring La I line (wavelength 6519.869 Å) we introduced another even parity energy level involved in the formation of the line, 41207.994 cm −1, J = 13/2, A = 91.6(5) MHz, B = 170(50) MHz. We tried also to explain why in old tables the wavelength given was so differ...
Physica Scripta
The hyperfine structure of several spectral lines of the tantalum atom has been investigated by l... more The hyperfine structure of several spectral lines of the tantalum atom has been investigated by laser excitation in the spectral range 4180-7000 Å. We report the discovery of 14 new energy levels of even parity and 21 new energy levels of odd parity. For the new levels, besides their wave number, their total angular momentum quantum number J, their parity, as well as their magnetic dipole and electric quadrupole hyperfine interaction constants A and B were determined. We classified altogether 73 lines by means of laser spectroscopy in a hollow cathode discharge, 52 of them by laser excitation and 21 via fluorescence decay. Additionally, 120 lines, observed in high-resolution Fourier transform spectra, were classified by using their wave numbers and their characteristic hyperfine patterns.
Data is presented on 166 previously unknown energy levels of Th+ ions, observed using resonant tw... more Data is presented on 166 previously unknown energy levels of Th+ ions, observed using resonant two-step laser excitation of trapped ions. The levels are of even parity and within the energy range from 7.8 to 9.8 eV. Observed lines are listed.<br> The observed levels can be relevant for the excitation or decay of the Th-229m isomeric nuclear state which lies in this energy range.
Within this work investigations of the hyperfine structure of tantalum atom with LIF (Laser Induc... more Within this work investigations of the hyperfine structure of tantalum atom with LIF (Laser Induced Fluorescence) method in a hollow cathode discharge were performed. Two hitherto unclassified spectral lines were excited: λ=4835.614 Å and λ=4997.192 Å. For both transitions values of quantum number J (total angular momentum of electron shell) of the levels involved were determined. On the basis of hyperfine structure constants A and B the lower levels of the transitions could be identified. Values of energies of the lower levels and wavenumbers of the excited transitions yielded energy value of the common, as it proved, upper level for both transitions. The odd parity level of the energy 47418.095 ± 0.011 cm -1 , with total electron angular momentum quantum number J=1/2 and the value of hyperfine structure magnetic dipole interaction constant A=-661 ± 13 MHz (for J=1/2 electric quadrupole interaction constant B=0) is a newly discovered electron level of tantalum atom. On the basis of...
Physical Review A, 2018
The thorium nucleus with mass number A = 229 has attracted much interest because its extremely lo... more The thorium nucleus with mass number A = 229 has attracted much interest because its extremely low lying first excited isomeric state at about 8 eV opens the possibility for the development of a nuclear clock. However, neither the exact energy of this nuclear isomer nor properties, such as nuclear magnetic dipole and electric quadrupole moment are known to a high precision so far. The latter can be determined by investigating the hyperfine structure of thorium atoms or ions. Due to its electronic structure and the long lifetime of the nuclear isomeric state, Th 2+ is especially suitable for such kind of studies. In this letter we present a combined experimental and theoretical investigation of the hyperfine structure of the 229 Th 2+ ion in the nuclear ground and isomeric state. A very good agreement between theory and experiment is found for the nuclear ground state. Moreover, we use our calculations to confirm the recently presented experimental value for the nuclear magnetic dipole moment of the thorium nuclear isomer, which was in contradiction to previous theoretical studies.
The European Physical Journal Special Topics, 2013
The experimental work of L. Windholz, G.H. Guthöhrlein and co-workers, concerning observation of ... more The experimental work of L. Windholz, G.H. Guthöhrlein and co-workers, concerning observation of the tantalum spectrum, yield many information about new energy levels and hyperfine structure splitting. We contribute the results of the complex parametric studies of the fine-and hyperfine structure of the mentioned element up to second-order of perturbation theory, including the effects of closed shell-open shell excitations. The work has been performed for the systems including 47 even configurations. The values of the radial parameters describing the one-and many-body interactions effects on atomic structure are given. We predicted values of energy levels and their A-and B-hyperfine structure constants, also for experimentally levels not observed up to now.
Using resonant two-step laser excitation of trapped ^232Th^+ ions, we observe 166 previously unkn... more Using resonant two-step laser excitation of trapped ^232Th^+ ions, we observe 166 previously unknown energy levels of even parity within the energy range from 7.8 to 9.8 eV and angular momenta from J=1/2 to 7/2. We also classify the high-lying levels observed in our earlier experiments by the total angular momentum and perform ab-initio calculations to compare their results with the observed level density. The observed levels can be relevant for the excitation or decay of the ^229mTh isomeric nuclear state which lies in this energy range. The high density of electronic levels promises a strongly enhanced electronic bridge excitation of the isomer in ^229Th^+.
Supplementary Information Nature 556:321-325. The figures show 29 of the 35 two-step excitation s... more Supplementary Information Nature 556:321-325. The figures show 29 of the 35 two-step excitation spectra recorded using the trap at LMU with copropagating beam configuration (six spectra do not contain detectable resonance features) and all spectra with counterpropagating configuration. The tables list the resonances and the corresponding transitions. See contents page for details.
Nature, Apr 1, 2018
The isotope Th is the only nucleus known to possess an excited state Th in the energy range of a ... more The isotope Th is the only nucleus known to possess an excited state Th in the energy range of a few electronvolts-a transition energy typical for electrons in the valence shell of atoms, but about four orders of magnitude lower than typical nuclear excitation energies. Of the many applications that have been proposed for this nuclear system, which is accessible by optical methods, the most promising is a highly precise nuclear clock that outperforms existing atomic timekeepers. Here we present the laser spectroscopic investigation of the hyperfine structure of the doubly charged Th ion and the determination of the fundamental nuclear properties of the isomer, namely, its magnetic dipole and electric quadrupole moments, as well as its nuclear charge radius. Following the recent direct detection of this long-sought isomer, we provide detailed insight into its nuclear structure and present a method for its non-destructive optical detection.
Journal of Physics B: Atomic, Molecular and Optical Physics, 2014
ABSTRACT Laser excitation of an Ar-La plasma, generated in a hollow cathode discharge lamp, has a... more ABSTRACT Laser excitation of an Ar-La plasma, generated in a hollow cathode discharge lamp, has allowed to us observe a huge number of spectral lines that could not be interpreted as transitions between already known La energy levels. From the observed hyperfine structure patterns and fluorescence lines, we derived 37 new La levels, all with even parity, in the energy range between 38 000 cm(-1) and 43 000 cm(-1). The existence of these levels was then proved by excitations from other known lower levels.
Physical Review Letters, 2018
The strong La line 6520.644 Å is present in a Fourier Transform Spectrum (signal to noise ratio o... more The strong La line 6520.644 Å is present in a Fourier Transform Spectrum (signal to noise ratio of 240), but its wavelength in commonly used tables (e.g. [1]) is given as 6520.770 Å, while in [2] the wavelength is given as 6520.74 Å, unclassified, with the remark “h ” (hazy). The line could not be classified using known energy levels of the La atom (La I) and its first ion (La II). It appears as a single broadened peak. By a combination of laser optogalvanic spectroscopy, laser-induced fluorescence and Doppler-reduced saturation spectroscopy we could introduce a new even parity La I energy level, 35449.041 cm −1, J = 13/2, with hyperfine (hf) constants A = −8.0(5) MHz, B = 10(10) MHz. For a second, up to now unknown neighbouring La I line (wavelength 6519.869 Å) we introduced another even parity energy level involved in the formation of the line, 41207.994 cm −1, J = 13/2, A = 91.6(5) MHz, B = 170(50) MHz. We tried also to explain why in old tables the wavelength given was so differ...
Physica Scripta
The hyperfine structure of several spectral lines of the tantalum atom has been investigated by l... more The hyperfine structure of several spectral lines of the tantalum atom has been investigated by laser excitation in the spectral range 4180-7000 Å. We report the discovery of 14 new energy levels of even parity and 21 new energy levels of odd parity. For the new levels, besides their wave number, their total angular momentum quantum number J, their parity, as well as their magnetic dipole and electric quadrupole hyperfine interaction constants A and B were determined. We classified altogether 73 lines by means of laser spectroscopy in a hollow cathode discharge, 52 of them by laser excitation and 21 via fluorescence decay. Additionally, 120 lines, observed in high-resolution Fourier transform spectra, were classified by using their wave numbers and their characteristic hyperfine patterns.